Quantum dot polarizer and manufacturing method thereof

ABSTRACT

A quantum dot polarizer includes a polarization layer and a first protective layer and a second protective layer respectively arranged on two opposite sides of the polarization layer. One of the first and second protective layers includes a complex film containing quantum dots distributed therein. A surface protective film is arranged on the first protective layer. An adhesive layer is arranged on the second protection layer. A peel-off film is arranged on the adhesive layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of co-pending U.S. patent applicationSer. No. 14/908,130, filed on Jan. 28, 2016, which is a national stageof PCT Application No. PCT/CN2015/098143, filed on Dec. 21, 2015,claiming foreign priority of Chinese Patent Application No.201510618855.5, filed on Sep. 24, 2015.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to the field of display, and in particularto a quantum dot (QD) polarizer and manufacturing method thereof.

2. The Related Arts

To meet the demands on the display for wide spectrum and colorsaturation, an effective option for major display manufacturers is toadd photoluminescence quantum dots (QD) in the backlight structure.

In use of QD as a nano-scale material, the quantum confinement effect isobvious because of the narrow size (<10 nano). When excited by light,and the excitation energy level exceeds the band gap, the electrons leapfrom valence band to conduction band, and emitted in an optical energyto form different colors. Also, by controlling the size of QD, differentcolors can be adjusted. Using the blue light from the light emittingdiode (LED) is able to effectively increase the color spectrum of thedisplay.

The known mainstream QD backlight technologies are divided into twoapproaches: one is to package the QD into a glass tube and placed infront of the backlight; and the other is to manufacture the QD into athin film for insertion between the backlight module and the displaypanel. Understandably, these technologies require specific facility formanufacturing QD, and thus increase cost.

As shown in FIG. 1, a common polarizer has a layered structure, from topdown, comprising: a surface protective film 110, a first protectivelayer 120, a polarization layer 130, a second protective layer 140, anadhesive layer 150, and a peel-off protective film 160, wherein whenattaching the polarizer, the peel-off film 160 is peeled off to exposethe adhesive layer 150. After the polarizer is attached, the surfaceprotective film 110 will be peeled off. The core of the structure of thepolarizer is the polarization layer 130, which usually comprises apolyvinyl alcohol (PVA) layer with iodine molecules able to polarize;and the first protective layer 120 and the second protective layer 140are transparent cellulose triacetate (TAC) layer, mainly to maintain thepolarization molecules in the polarization layer 130 to stay extended toavoid dehydration and to protect from external influence.

Therefore, the layered structure of the polarizer is suitable for addingQD film, such as, China Patent CN102854558 and Korea PatentKR20070107498A, disclosed methods for adding a QD layer, i.e., a quantumbar layer with polarization effect between the protective layer and thepolarization layer. However, these methods require additional QD layerprocess, which leads to degraded transmittance, higher cost and thickerdisplay devices.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a quantum dotpolarizer, able to improve color spectrum and transmittance of thedisplay, without increase the thickness of the display, suitable forultra-thin applications.

Another object of the present invention is to provide a manufacturingmethod for quantum dot polarizer, directly doping the quantum dots intothe cotton glue for protective layer to manufacture a protective layerwith quantum dots, so as to manufacture quantum dot polarizer, toeliminate the preparation of independent quantum dot elements for thebacklight module to reduce the cost.

To achieve the above object, the present invention provides a quantumdot polarizer, which comprises a polarization layer, a first protectivelayer and a second protective layer, disposed respectively on the twosides of the polarization layer, a surface protective film disposed onthe first protective layer, an adhesive layer disposed on the secondprotection layer and a peel-off film disposed on the adhesive layer;wherein the first protective layer or the second protective layer beinga complex film comprising quantum dots.

When the quantum dot polarizer is used as an upper polarizer for an LCDpanel, the first protective layer is the complex film comprising quantumdots.

When the quantum dot polarizer is used as a lower polarizer for an LCDpanel, the second protective layer is the complex film comprisingquantum dots.

The present invention also provides a manufacturing method for quantumdot polarizer, which comprises: Step 1: preparing a cotton glue forquantum dot protective layer; Step 2: forming a complex film comprisingquantum dots with the cotton glue to obtain a quantum dot protectivelayer through an extension process or a coating process; Step 3: usingthe quantum dot protective layer to manufacture the quantum dotpolarizer; wherein the quantum dot polarizer comprising a polarizationlayer, a first protective layer and a second protective layer, disposedrespectively on the two sides of the polarization layer, a surfaceprotective film disposed on the first protective layer, an adhesivelayer disposed on the second protection layer and a peel-off filmdisposed on the adhesive layer; and the first protective layer or thesecond protective layer being a quantum dots protective layer obtainedin Step 2; Step 1 comprising the following steps: Step 11: mixing amaterial for the protective layer and a solution, slowly stirring at aspeed of 10-22 rpm/min for 1-3 hours; Step 12: accelerating stirringspeed to 23-38 rpm/min for 2-3.5 hours; Step 13: accelerating stirringspeed to 40-60 rpm/min for 1.5-2.5 hours; Step 14: slowing down stirringspeed to 10-22 rpm/min for 0.5-2 hours; Step 1 further comprising:adding plasticizer in any one of the above Steps 11-14 to obtain aprotective layer solution with better solubility; and adding quantumdots in any one of the above Steps 11-14.

The quantum dots are one or more of the following doped or non-dopedquantum dots: ZnS, CdS, ZnO, GaN, GaSe, ZnSe, CdSe, ZnTe, CdTe, PbTe,InP, CdAs.

The quantum dots are graphene quantum dots or carbon quantum dots.

In Step 11, the material for the protective layer is polytriacetylcellulose with 250-350 degree of polymerization.

In Step 11, the solution comprises a primary solution and an auxiliarysolution, the primary solution is dichloromethane, and the auxiliarysolution is methanol, ethanol, or butanol.

The plasticizer is a mixed plasticizer comprising a primary plasticizerand an auxiliary plasticizer, the primary plasticizer is triphenylphosphate, and the auxiliary plasticizer is one or more of thefollowing: dibutyl phthalate, butoxyethyl phthalate, and octylphthalate.

In Step 11, the stirring time is 2 hours; in Step 12, the stirring timeis 3 hours; in Step 13, the stirring time is 2 hours; and in Step 14,the stirring time is 1 hour.

The present invention also provides a manufacturing method for quantumdot polarizer, which comprises: Step 1: preparing a cotton glue forquantum dot protective layer; Step 2: forming a complex film comprisingquantum dots with the cotton glue to obtain a quantum dot protectivelayer through an extension process or a coating process; Step 3: usingthe quantum dot protective layer to manufacture the quantum dotpolarizer; wherein the quantum dot polarizer comprising a polarizationlayer, a first protective layer and a second protective layer, disposedrespectively on the two sides of the polarization layer, a surfaceprotective film disposed on the first protective layer, an adhesivelayer disposed on the second protection layer and a peel-off filmdisposed on the adhesive layer; and the first protective layer or thesecond protective layer being a quantum dots protective layer obtainedin Step 2; Step 1 comprising the following steps: Step 11: mixing amaterial for the protective layer and a solution, slowly stirring at aspeed of 10-22 rpm/min for 1-3 hours; Step 12: accelerating stirringspeed to 23-38 rpm/min for 2-3.5 hours; Step 13: accelerating stirringspeed to 40-60 rpm/min for 1.5-2.5 hours; Step 14: slowing down stirringspeed to 10-22 rpm/min for 0.5-2 hours; Step 1 further comprising:adding plasticizer in any one of the above Steps 11-14 to obtain aprotective layer solution with better solubility; and adding quantumdots in any one of the above Steps 11-14; in Step 11, the material forthe protective layer is poly triacetylcellulose with 250-350 degree ofpolymerization; in Step 11, the solution comprises a primary solutionand an auxiliary solution, the primary solution is dichloromethane, andthe auxiliary solution is methanol, ethanol, or butanol; the plasticizeris a mixed plasticizer comprising a primary plasticizer and an auxiliaryplasticizer, the primary plasticizer is triphenyl phosphate, and theauxiliary plasticizer is one or more of the following: dibutylphthalate, butoxyethyl phthalate, and octyl phthalate.

Compared to the known techniques, the present invention provides thefollowing advantages: the present invention provides a quantum dotpolarizer and manufacturing method thereof. The quantum dot polarizercomprises a first protective layer and a second protective layer, andthe first protective layer or the second protective layer being acomplex film comprising quantum dots. As such, without increasing thethickness of display, the invention can improve color spectrum andtransmittance, and is applicable to ultra-thin display devices at lowcost. The manufacturing method adds the quantum dots to the cotton gluefor forming protective layers by extension or coating process to obtainquantum dot protective layer used for quantum dot polarizer. As such,the invention can avoid humidity and oxygen affecting the quantum dotsand reduce cost by eliminating manufacturing independent quantum dotelement separately.

BRIEF DESCRIPTION OF THE DRAWINGS

To make the technical solution of the embodiments according to thepresent invention, a brief description of the drawings that arenecessary for the illustration of the embodiments will be given asfollows. Apparently, the drawings described below show only exampleembodiments of the present invention and for those having ordinaryskills in the art, other drawings may be easily obtained from thesedrawings without paying any creative effort. In the drawings:

FIG. 1 is a schematic view showing the structure for a known polarizer;

FIG. 2 is a schematic view showing the structure of the first embodimentof a quantum dot polarizer provided by an embodiment of the presentinvention; and

FIG. 3 is a schematic view showing the structure of the secondembodiment of a quantum dot polarizer provided by an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To further explain the technical means and effect of the presentinvention, the following refers to embodiments and drawings for detaileddescription.

Referring to FIGS. 2-3, the present invention provides a quantum dotpolarizer, which comprises: a polarization layer 13, a first protectivelayer 12 and a second protective layer 14, disposed respectively on thetwo sides of the polarization layer 13, a surface protective film 11disposed on the first protective layer 12, an adhesive layer 15 disposedon the second protection layer 14 and a peel-off film 16 disposed on theadhesive layer 15; wherein the first protective layer 12 or the secondprotective layer 14 being a complex film comprising quantum dots 121.

Specifically, when the quantum dot polarizer is used for a liquidcrystal display (LCD) panel, to prevent quantum dots from changing thelinear polarization state, the first protective layer 12 or the secondprotective layer 14 comprising quantum dots 121 must be disposed at theside away from the backlight module of the LCD panel.

As shown in FIG. 2, in the first embodiment of the present invention,the quantum dot polarizer is used as the upper polarizer in the LCDpanel, and the first protective layer 12 is the complex film comprisingquantum dots 121. The quantum dot polarizer comprises, from top tobottom, the surface protective film 11, the first protective layer 12,the polarization layer 13, the second protective layer 14, the adhesivelayer 15 and the peel-off protective film 16.

As shown in FIG. 3, in the second embodiment of the present invention,the quantum dot polarizer is used as the lower polarizer in the LCDpanel, and the second protective layer 14 is the complex film comprisingquantum dots 121. The quantum dot polarizer comprises, from top tobottom, the surface protective film 11, the first protective layer 12,the polarization layer 13, the second protective layer 14, the adhesivelayer 15 and the peel-off protective film 16.

The quantum dot polarizer of the present invention comprises a firstprotective layer and a second protective layer, and the first protectivelayer or the second protective layer being a complex film comprisingquantum dots. As such, without increasing the thickness of display, theinvention can improve color spectrum and transmittance, and isapplicable to ultra-thin display devices at low cost.

The present invention also provides a manufacturing method for quantumdot polarizer, which comprises:

Step 1: preparing a cotton glue for quantum dot protective layer;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer;

Wherein the quantum dot polarizer comprises a polarization layer 13, afirst protective layer 12 and a second protective layer 14, disposedrespectively on the two sides of the polarization layer 13, a surfaceprotective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Specifically, Step 1 comprises the following steps:

Step 11: mixing a material for the protective layer and a solution,slowly stirring at a speed of 10-22 rpm/min for 1-3 hours;

Step 12: accelerating stirring speed to 23-38 rpm/min for 2-3.5 hours;

Step 13: accelerating stirring speed to 40-60 rpm/min for 1.5-2.5 hours;and

Step 14: slowing down stirring speed to 10-22 rpm/min for 0.5-2 hours.

Step 1 further comprises: adding plasticizer in any one of the aboveSteps 11-14 to obtain a protective layer solution with bettersolubility; and adding quantum dots in any one of the above Steps 11-14.

Specifically, in Step 11, the material for the protective layer is polytriacetylcellulose with 250-350 degree of polymerization; in Step 11,the solution comprises a primary solution and an auxiliary solution, theprimary solution is dichloromethane, and the auxiliary solution ismethanol, ethanol, or butanol.

Specifically, the quantum dots are one or more of the following doped ornon-doped quantum dots: ZnS, CdS, ZnO, GaN, GaSe, ZnSe, CdSe, ZnTe,CdTe, PbTe, InP, CdAs; or, the quantum dots are graphene quantum dots orcarbon quantum dots; the plasticizer is a mixed plasticizer comprising aprimary plasticizer and an auxiliary plasticizer, the primaryplasticizer is triphenyl phosphate, and the auxiliary plasticizer is oneor more of the following: dibutyl phthalate, butoxyethyl phthalate, andoctyl phthalate.

The following is a preferred embodiment of the manufacturing method forquantum dot polarizer of the present invention.

Embodiment 1

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 10 rpm/min for 3 hours;

Step 12: accelerating stirring speed to 23 rpm/min, adding plasticizer,stirring for 3.5 hours;

Step 13: accelerating stirring speed to 40 rpm/min for 2.5 hours; and

Step 14: slowing down stirring speed to 10 rpm/min, adding quantum dots,stirring for 2 hours to obtain the cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer.

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Embodiment 2

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 22 rpm/min for 1 hour;

Step 12: accelerating stirring speed to 38 rpm/min, adding plasticizer,stirring for 2 hours;

Step 13: accelerating stirring speed to 60 rpm/min for 1.5 hours; and

Step 14: slowing down stirring speed to 22 rpm/min, adding quantum dots,stirring for 0.5 hour to obtain the cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer;

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Embodiment 3

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 15 rpm/min for 2 hours;

Step 12: accelerating stirring speed to 30 rpm/min, adding plasticizer,stirring for 3 hours;

Step 13: accelerating stirring speed to 50 rpm/min for 2 hours; and

Step 14: slowing down stirring speed to 20 rpm/min, adding quantum dots,stirring for 1 hour to obtain the cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer.

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Embodiment 4

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 15 rpm/min for 2 hours;

Step 12: accelerating stirring speed to 30 rpm/min for 3 hours;

Step 13: accelerating stirring speed to 50 rpm/min, adding plasticizer,stirring for 2 hours; and

Step 14: slowing down stirring speed to 210 rpm/min, adding quantumdots, stirring for 1 hour to obtain the cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer;

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Embodiment 5

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 15 rpm/min for 2 hours;

Step 12: accelerating stirring speed to 30 rpm/min for 3 hours;

Step 13: accelerating stirring speed to 50 rpm/min, adding plasticizerand quantum dots, stirring for 2.5 hours; and

Step 14: slowing down stirring speed to 10 rpm/min for 2 hours to obtainthe cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer.

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

Embodiment 6

Step 1: preparing a cotton glue for quantum dot protective layer;specifically, Step 1 comprising:

Step 11: mixing the protective layer material TAC and a solution, slowlystirring at a speed of 15 rpm/min for 2 hours;

Step 12: accelerating stirring speed to 30 rpm/min, adding plasticizer,stirring for 3 hours;

Step 13: accelerating stirring speed to 50 rpm/min, adding quantum dots,stirring for 2 hours; and

Step 14: slowing down stirring speed to 20 rpm/min for 1 hour to obtainthe cotton glue with quantum dots;

Step 2: forming a complex film comprising quantum dots with the cottonglue to obtain a quantum dot protective layer through an extensionprocess or a coating process; and

Step 3: using the quantum dot protective layer to manufacture thequantum dot polarizer.

Specifically, the quantum dot polarizer comprises a polarization layer13, a first protective layer 12 and a second protective layer 14,disposed respectively on the two sides of the polarization layer 13, asurface protective film 11 disposed on the first protective layer 12, anadhesive layer 15 disposed on the second protection layer 14 and apeel-off film 16 disposed on the adhesive layer 15; and the firstprotective layer 12 or the second protective layer 14 is a quantum dotsprotective layer obtained in Step 2.

In summary, the present invention provides a quantum dot polarizer andmanufacturing method thereof. The quantum dot polarizer comprises afirst protective layer and a second protective layer, and the firstprotective layer or the second protective layer being a complex filmcomprising quantum dots. As such, without increasing the thickness ofdisplay, the invention can improve color spectrum and transmittance, andis applicable to ultra-thin display devices at low cost. Themanufacturing method adds the quantum dots to the cotton glue forforming protective layers by extension or coating process to obtainquantum dot protective layer used for quantum dot polarizer. As such,the invention can avoid humidity and oxygen affecting the quantum dotsand reduce cost by eliminating manufacturing independent quantum dotelement separately.

It should be noted that in the present disclosure the terms, such as,first, second are only for distinguishing an entity or operation fromanother entity or operation, and does not imply any specific relation ororder between the entities or operations. Also, the terms “comprises”,“include”, and other similar variations, do not exclude the inclusion ofother non-listed elements. Without further restrictions, the expression“comprises a . . . ” does not exclude other identical elements frompresence besides the listed elements.

Embodiments of the present invention have been described, but notintending to impose any unduly constraint to the appended claims. Anymodification of equivalent structure or equivalent process madeaccording to the disclosure and drawings of the present invention, orany application thereof, directly or indirectly, to other related fieldsof technique, is considered encompassed in the scope of protectiondefined by the claims of the present invention.

What is claimed is:
 1. A quantum dot polarizer, comprising apolarization layer, a first protective layer and a second protectivelayer that are respectively arranged on two opposite sides of thepolarization layer, a surface protective film arranged on the firstprotective layer, an adhesive layer arranged on the second protectionlayer, and a peel-off film arranged on the adhesive layer; wherein oneof the first protective layer and the second protective layer comprisesa complex film that is formed of a material containing quantum dotsdistributed therein.
 2. The quantum dot polarizer as claimed in claim 1,wherein the quantum dot polarizer is adapted to attach to a liquidcrystal display panel to serve as an upper polarizer of the liquidcrystal display and the first protective layer comprises the complexfilm that contains the quantum dots distributed therein.
 3. The quantumdot polarizer as claimed in claim 1, wherein the quantum dot polarizeris adapted to attach to a liquid crystal display panel to serve as alower polarizer of the liquid crystal display and the second protectivelayer comprises the complex film that contains the quantum dotsdistributed therein.
 4. The quantum dot polarizer as claimed in claim 1,wherein the quantum dots are doped or non-doped quantum dots that areselected from one or more of the following materials: ZnS, CdS, ZnO,GaN, GaSe, ZnSe, CdSe, ZnTe, CdTe, PbTe, InP, CdAs.
 5. The quantum dotpolarizer as claimed in claim 1, wherein the quantum dots are graphenequantum dots or carbon quantum dots.
 6. The quantum dot polarizer asclaimed in claim 1, wherein the complex film is formed of polytriacetylcellulose that has a degree of polymerization of 250-350
 7. Thequantum dot polarizer as claimed in claim 6, wherein the quantum dotsare doped or non-doped quantum dots that are selected from one or moreof the following materials: ZnS, CdS, ZnO, GaN, GaSe, ZnSe, CdSe, ZnTe,CdTe, PbTe, InP, CdAs.
 8. The quantum dot polarizer as claimed in claim6, wherein the quantum dots are graphene quantum dots or carbon quantumdots.